Elementary Charge and Charge Transfer

Elementary Charge Facts

• Elementary charge is measured in Coulombs
• One elementary charge equals 1.6 x 10^-19 C
• A proton has a positive charge
• An electron has a negative charge
• Particles with the same charge repel each other
• Particles with different charges attract each other
• The only particle that moves is the electron
• The Law of Conservation of Charge states that charge cannot be created or destroyed, only transferred
• When two charged objects are brought into contact, their charges will equalize or be shared

Transfer of Charge Facts

• A good conductor allows electrons to flow easily
• An insulator does not allow electrons to flow easily
• When charging an object by friction, two insulators are rubbed together giving a positive charge to one and a negative charge to the other
• When an object is grounded, it is placed in contact with the Earth, making the object neutral
• When charging an object by induction, a charged object is brought near a neutral object, without touching
• This creates a temporary polarization, resulting in positive and negative sides of the object
• Electrons flow toward the positive side, and when the charged object is removed, the initially neutral object returns to neutral
• Charging an object by conduction is achieved by bringing a charged object near and touching a neutral object
• This gives the neutral object the same charge as the original charged object
• After the charged object is removed, the contacted neutral object stays charged.
• An object can be charged by induction/ground